综合类B级：完形填空Less Is More
It sounds all wrong--drilling holes in a piece of wood to make it more resistant to knocks.But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot.The discovery should lead to more effective and lighter packaging materials. Carpenters have known ________(51)centuries that some woods are tougher than others.Hickory(山核桃木)，for example，was turned into axe handles and cartwheel spokes(轮辐)because it Can absorb shocks without breaking.White oak，for example，is much more easily
damaged，_________ (52)it is almost as dense.Julian Vincent at Bathe University and his team were convinced the wood’s internal structure could explain the differences.
Many trees have tubular(管的)vessels that run _________ (53)the trunk and carry water to the leaves.In oak they are large，and arranged in narrow bands，but in hickory they are smaller，and more evenly distributed.The researchers _________ (54)this layout might distribute a blow’s energy throughout the wood.soaking up a bigger hit.To test the idea，they drilled holes 0.65 millimetres across into a block of spruce(云杉)，a wood with _________ (55)vessels，and found that _________ (56)withstood a harder knock._________ (57)when there were more than about 30 holes per square centimetre did the wood’s performance drop off.
A uniform substance doesn’t cope well with knocks because only a small proportion of the material is actually _________ (58).All the energy from the blow goes towards breaking the material in one or two places，but often the pieces left _________ (59)are pristine(未经破坏的).
But instead of the energy being concentrated in one place，the holes provide many weak spots that all absorb energy as they break，says Vincent.“You are controlling the places_________ (60)the wood breaks，and it can then absorb more _________ (61)，more safely.”The researchers believe the principle could be applied to any material- _________ (62)example.to manufacture lighter and more protective packaging.It could _________ (63)be used in Car bumpers，crash barriers and armour for military vehicles，says Ulrike Wegst， _________ (64)the Max Plank Institute for Mental Research in Stuttgart.But she emphasizes that you _________ (65)to design the substance with the direction of force in mind.“The direction of loading is crucial，”she says.
51 A in B since C for D at
52 A or B although C and D despite
53 A down B over C up D into
54 A knew B concluded C saw D thought
55 A no B per C each D every
56 A it B the idea C they D spruce
57 A if B Just C Only D Rarely
58 A effected B beaten C slapped D affected
59 A behind B beyond C for D in
60 A which B there C that D where
61 A water B air C energy D safety
62 A among B in C as D for
63 A also B besides C else D yet
64 A over B at C around D on
65 A have B must C should D had
参考答案：
51.答案为C for centuries表示几个世纪以来，注意在用现在完成时的句子里for后面跟一段时间，since后面跟一点时间。
52.答案为B 这里需要一个连接词，但要表达“虽然”这样的让步意义。
53.答案为c 树叶在树的上部，所以在树干里把水分送到树叶里去的管道应该说是run up the trunk，而不是run down the trunk.
54.答案为D 这里所说的仅仅是一个假设，注意情态动词might，表示这还仅仅是一种可能，后面说要对此进行test.
55.答案为A 除了no，其他几个选项根本不可能用在这里。
56.答案为A 这里需要一个单数的代词，代替spruce或者the wood.
57.答案为C Only放在when从句前面起强调作用，表示“只有当……时”，注意后面的句子是倒装的，就是因为用了Only的要求。
58.答案为D‘ affected受到影响，effect(效力，生效)在词形上容易和affect混淆。beat(打)，slap(打耳光)在这里毫不相干。
59.答案为A to be left behind是“被留下”的意思，又如：Those who were left behind were soon found bv the enemy.留下来的那些人很快就被敌人发现了。
60.答案为D 这里填入的是一个引导定语从句的连接词，因为先行词是places，所以应该选where.61.答案为C 这里都在讲能量的吸收，很自然这里应该填入energy.
62.答案为D for example(例如)，是个十分普通的固定的表达方式。
63.答案为A “也能用于……”，只有also可以考虑。
64.答案为B 表示在某个单位或机构任职用at.
65.答案为A 后面有to，所以不可能用must或should，have to表示“必须，不得不”。